Vests and other apparel have previously been modified to include liquid or other materials to actively cool the wearer and/or protect the wearer from high heat. As an example, cooling garments and/or protective garments are described in U.S. Pat. No. 4,580,408, U.S. Pat. No. 5,606,746 and U.S. Pat. No. 5,885,912. Cooling is achieved by evaporation of water or other volatile liquid from the garment. Cooling garments are commonly worn while the wearer is active and including when the wearer is undertaking strenuous activity. In this regard, many absorbent layers can lose retained water during the activity as a result of the bending and creasing of the garment that occurs naturally through use. Further, compression of the absorbent layer while saturated can cause dislodging of the absorbent material and/or formation of clumps of the absorbent material. This can reduce absorbency of the materials, reduce the rate of evaporation and/or provide for uneven cooling across the garment. Thus, cooling garments having an absorbent layer that can better withstand the applied forces associated with the physical activity of the wearer are desired. In addition, often the conditions under which the cooling vests are worn expose the worker to unpleasant and/or unhealthy materials and in such instances it may be necessary and/or desirable to dispose of the garment after several or even a single use. Accordingly, cooling garments that can withstand the physical activity of the wearer and yet which can be provided economically so as to be capable of being a single-use or multi-use product are also highly desirable.
The aforesaid needs are fulfilled and the shortcomings of the prior art overcome by a cooling garment of the present invention which is a durable multilayer laminate adapted to be worn about the body and comprises (a) an inner barrier layer comprising a thermoplastic polymer material having a hydrohead of at least about 35 mbar and a water vapor transmission rate of at least about 800 g/m2/24 hours; (b) an outer reinforcing layer comprising a web of thermoplastic polymer fibers and having a hydrohead less than about 25 mbar and a water vapor transmission rate of at least about 800 g/m2/24 hours; (c) an absorbent layer, disposed between the barrier layer and the reinforcing layer, comprising a stabilized matrix of about 55% to 95% cellulosic fibers and from about 5% to 45% thermoplastic polymer fibers. The absorbent layer is desirably regionally bonded wherein the bond area comprises less than about 20% of the surface area of the laminate. Further, the absorbent layer may be bonded to at least one of the outer reinforcing layer or the inner barrier layer by regionally applying sufficient energy to the layers such that the thermoplastic polymer melts and resolidifies to form inter-fiber bonds. In one aspect, the bonded regions may comprise a series of continuous bonding lines or a series of staggered discontinuous line segments. Desirably, the bonding lines or segments extend substantially horizontally when the garment is worn. Still further, the edges of the cooling garment may be continuously bonded and form a substantially liquid impervious seal. The cooling garment can comprise one or more articles such as, for example, vests, shirts, pants, gowns, jump-suits, caps, and so forth.
As used herein and in the claims, the term xe2x80x9ccomprisingxe2x80x9d is inclusive or open-ended and does not exclude additional unrecited elements, compositional components, or method steps. Accordingly, the term xe2x80x9ccomprisingxe2x80x9d encompasses the more restrictive terms xe2x80x9cconsisting essentially ofxe2x80x9d and xe2x80x9cconsisting of.xe2x80x9d
As used herein, all percentages, ratios and proportions are by weight unless otherwise specified.
As used herein the term xe2x80x9cnonwovenxe2x80x9d fabric or web means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted or woven fabric. Nonwoven fabrics or webs have been formed by many processes such as, for example, meltblowing processes, spunbonding processes, conforming, hydroentangling, air-laid and bonded carded web processes.
As used herein, the term xe2x80x9cspunbonded fibersxe2x80x9d refers to fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, U.S. Pat. No. 4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to Hartman; U.S. Pat. No. 3,542,615 to Dobo et al.; and U.S. Pat. No. 5,382,400 to Pike et al.; the entire content of each is incorporated herein by reference. Spunbond fibers are generally not tacky when they are deposited onto a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns to about 50 or 60 microns, often, between about 15 and 25 microns.
As used herein, the term xe2x80x9cmeltblown fibersxe2x80x9d means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241. Meltblown fibers are microfibers, which may be continuous or discontinuous, and are generally smaller than 10 microns in average diameter, and are generally tacky when deposited onto a collecting surface.
As used herein, the term xe2x80x9cpolymerxe2x80x9d generally includes, but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term xe2x80x9cpolymerxe2x80x9d shall include all possible geometrical configurations of the molecule. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
As used herein a xe2x80x9csuperabsorbentxe2x80x9d or xe2x80x9csuperabsorbent materialxe2x80x9d refers to a water-swellable, water-soluble organic or inorganic material capable, under favorable conditions, of absorbing at least about 10 times its weight and, more desirably, at least about 20 times its weight in water. Organic materials suitable for use as a superabsorbent material in conjunction with the present invention include, but are not limited to, natural materials such as guar gum, agar, pectin and the like; as well as synthetic materials, such as synthetic hydrogel polymers. Such hydrogel polymers include, for example, alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene, maleic anhydride copolymers, polyvinyl ethers, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, polyvinylmorpholinone, and polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, polyvinylpyrridine, and the like. Other suitable polymers include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, and isobutylene maleic anhydride polymers and mixtures thereof. The hydrogel polymers are preferably lightly crosslinked to render the materials substantially water insoluble. Crosslinking may, for example, be accomplished by irradiation or by covalent, ionic, van der Waals, or hydrogen bonding. The superabsorbent materials may be in any form suitable for use in absorbent composites including particles, fibers, flakes, spheres and so forth. Superabsorbents are generally available in particle sizes ranging from about 20 to about 1000 microns.
As used herein, the term xe2x80x9cconform materialxe2x80x9d means composite materials comprising a mixture or stabilized matrix of thermoplastic fibers and a second non-thermoplastic material. As an example, conform materials may be made by a process in which at least one meltblown die head is arranged near a chute through which the non-thermoplastic material are added to the web while it is forming. The second non-thermoplastic material may be, for example, pulp, superabsorbent particles, cellulose fibers, staple fibers and other particles. In the present invention, the non-thermoplastic material is the combination of the absorbent material and the odor controlling material. Exemplary conform materials are disclosed in commonly assigned U.S. Pat. No. 5,284,703 to Everhart et al.; U.S. Pat. No. 5,350,624 to Georger et al.; and U.S. Pat. No. 4,100,324 to Anderson et al.; the entire content of each is incorporated herein by reference.
As used herein, the term xe2x80x9cporousxe2x80x9d refers to a substrate or material that has interstitial spaces or openings located therein such that there exist pathways that extend through the entire thickness of the material, individual interstitial spaces need not extend through the entire thickness of the material and can collectively form pathways through the material via adjacent, inter-connecting spaces.
The term xe2x80x9cdenierxe2x80x9d is defined as grams per 9000 meters of a fiber. For a fiber having circular cross-section, denier may be calculated as fiber diameter in microns squared, multiplied by the density in grams/cc, multiplied by 0.00707. A lower denier indicates a finer fiber and a higher denier indicates a thicker or heavier fiber. Outside the United States the unit of measurement is more commonly the xe2x80x9ctex,xe2x80x9d which is defined as the grams per kilometer of fiber. Tex may be calculated as denier/9. The xe2x80x9cmean fiber denierxe2x80x9d is the sum of the deniers for each fiber, divided by the number of fibers.
As used herein, the term xe2x80x9cmachine-directionxe2x80x9d or MD means the direction of a fabric corresponding to the direction in which it was produced. The term xe2x80x9ccross-directionxe2x80x9d or CD means the direction of a fabric generally perpendicular to the MD.
As used herein, the term xe2x80x9cbody-sidexe2x80x9d or xe2x80x9cinnerxe2x80x9d refers to the side of a material that will face the wearer of the article and the term xe2x80x9couterxe2x80x9d refers to the opposing side that faces away from the body, i.e. distal to the body when the article incorporating the material is worn.